1. Field of the Invention
The present invention relates generally to integrated circuit fabrication, and more particularly to integrated circuit manufacturing equipment.
2. Description of the Background Art
Fabrication of an integrated circuit (IC) involves deposition of one or more layers of thin film on a wafer. For example, a dielectric material may be deposited on a wafer using a chemical vapor deposition (CVD) process. A deposition process may be performed using specialized manufacturing equipment. Typically, such an equipment includes a process chamber where a wafer is placed, and a mechanism for flowing materials into the process chamber. Depending on the process, the materials may need to be evaporated and mixed together prior to being flown into the process chamber.
FIG. 1A shows a top perspective view of a mechanism for introducing materials in an integrated circuit manufacturing equipment. As shown in FIG. 1A, a manifold 101 includes sections of metal tubing having a gas inlet 102 for receiving gaseous materials and a liquid injection point 103 for receiving liquid materials. A tubular silicon rubber heater 104 is wrapped around manifold 101 to facilitate evaporation of liquid materials. A section 105 of manifold 101 feeds into a top portion of a distributor 106, while a section 107 feeds into a bottom portion of distributor 106. From distributor 106, materials flow into plumbing lines 108 (i.e., 108A, 108B, 108C, 108D, 108E, and 108F) and into a process chamber located below distributor 106.
FIG. 1B shows a schematic diagram of the mechanism of FIG. 1A. Heater 104 is depicted in FIG. 1B as having sections 104A, 104B, and 104C. As shown in FIG. 1B, a plumbing line 108 is coupled to a shower head 121 directly overhead a wafer 122. Shower head 121 includes several holes through which materials are flown into a process chamber 120. Materials in process chamber 120 deposit on a wafer 122.
A problem with prior mechanisms for introducing materials in an integrated circuit manufacturing equipment is that they may clog if not properly maintained. Another problem with some of these mechanisms is that they do not optimally evaporate and mix materials.
The present invention relates to methods and apparatus for introducing materials in an integrated circuit manufacturing equipment. In one embodiment, a mixing device includes a nozzle that is disposed tangent to a wall of a chamber. Gas flowing from the nozzle rotates in the chamber forming a vortex. Another gas may be flown near a middle portion of the chamber, thereby uniformly mixing the two gases.
In another embodiment, an evaporation and mixing device includes a nozzle configured to impart rotation to a gas flowing into a chamber. An injector flows a liquid material near a middle portion of the chamber, thereby mixing the gas and the liquid material. A heater may be employed to help evaporate the liquid material.